///////////////////////////////////////////////////////////////////////////////
//                                                                           //
// DxilPoisonValues.h                                                        //
// Copyright (C) Microsoft Corporation. All rights reserved.                 //
// This file is distributed under the University of Illinois Open Source     //
// License. See LICENSE.TXT for details.                                     //
//                                                                           //
// Allows insertion of poisoned values with error messages that get          //
// cleaned up late in the compiler.                                          //
//                                                                           //
/////////////////////////////////////////////////////////////////////////////// 
#pragma once

#include "llvm/IR/DebugLoc.h"

namespace llvm {
  class Instruction;
  class Type;
  class Value;
  class Module;
}

namespace hlsl {
  // Create a special dx.poison.* instruction with debug location and an error message.
  // The reason for this is certain invalid code is allowed in the code as long as it is
  // removed by optimization at the end of compilation. We only want to emit the error
  // for real if we are sure the code with the problem is in the final DXIL.
  // 
  // This "emits" an error message with the specified type. If by the end the compilation
  // it is still used, then FinalizePoisonValues will emit the correct error for real.
  llvm::Value *CreatePoisonValue(llvm::Type *ty, const llvm::Twine &errMsg, llvm::DebugLoc DL, llvm::Instruction *InsertPt);

  // If there's any dx.poison.* values present in the module, emit them. Returns true
  // M was modified in any way.
  bool FinalizePoisonValues(llvm::Module &M);
}